Page 57 of 263

OperationoftheABSsystem
Awheelspeedsensorismountedtoeachofthe
fourwheels.Ifwheellock-upofeitherofthe
frontwheelsortherearwheelsissensedduring
braking,thebrakepressureisadjustedautomat-
icallyuntilthewheelnolongerslips.Thebrake
pressureisregulatedforeachfrontwheelindi-
viduallyandforbothoftherearwheels
together.
Onaroadsurfacewhichisslipperyononlyone
side,therearwheelwhichisbrakingontheslip-
perysurfacedeterminesthebrakepressure
whichwillbeappliedequallytobothrearwheels.
Thisensuresthatdirectionalstabilityismain-
tained.However,ifbrakingforcesapproachthe
wheellock-uppointforallwheels(panicbraking)
theABSsystemwillintervenetoprovidearapid
rythmicbraking.
TheproperoperationofABSisperceivedbythe
driverasapulsatingbrakepedalinconjunction
withaudiblenoiseandperhapssomevibration.
I>Ifyouexperiencethesesensationswhiledriv-
ingoraroadsurfacewithquestionabletrac-
tion,reducevehiclespeedappropriateforthe
prevailingroadconditions.
Thefunctionalreadinessofallthemainelectrical
componentsoftheABSischeckedbyanelec-
tronicmonitoringsystembothbeforeandwhile
youdrive.
8
WarninglightUSA
@
WarninglightCanada
WhentheignitionisswitchedontheABSwarn-
inglightwilllightupwhilethesystemiselec-
tronicallyinterrogatedandgoesoutwhenthe
engineisstartedifthecheckisnotyetcom-
plete.
IftheABSwarninglampfailstogoout,thisindi-
catesthatABShasbeendeactivatedduetoa
fault.Ifthewarninglightsintheinstrumentpanel
andon-boardcomputerlightupwhileyouare
driving,thisindicatesthatafaulthasoccurred.
Inbothcases,normalbraking,asinvehicles
withoutABS,isstillretained.
TheABSsystemshould,however,beexamined
atanauthorizedPorschedealerimmediatelyto
preventtheoccurrenceoffurtherfaults.
I>IftheABSsystembecomesinoperative,take
yourvehicletoyourauthorizedPorsche
dealerimmediately.
/!\Warning!
ThecontrolunitoftheABSbrakesystemis
setforstandardtiresize.Ifnon-standard
tiresareinstalled,thecontrolunitmaymis-
interpretthespeedofthevehicle,because
ofthevariantdataitreceivesfromthesen-
sorsontheaxles.
I>Useonlytiremakesandtypestestedby
Porsche.
Controls,Instruments
57
Page 58 of 263

PorscheStabilityManagement
(PSM)
PSMisanactivecontrolsystemforstabilizing
thevehicleduringextremedrivingmaneuvers.
/!\.Warning!
Theincreasedcontrolthatisprovided
shouldnotinduceyoutotakegreaterrisks
withyoursafety.Thelimitsdictatedbythe
lawsofphysicscannotbeovercome,even
withPSM.
Theriskofaccidentsduetoinappropriate
speedcannotbereduced,evenbyPSM.
Thedriverbearstheresponsibilityforall
drivingmaneuvers.
[>Adaptyourdrivingstyletotheprevailingroad
andweatherconditions.
[>Obeyalltrafficlaws.
AdvantagesofPSM
-Superiortractionandlane-holdingabilityinall
drivingsituations-evenonroadsurfaces
withvaryingfriction.
-PSMactivelystabilizesthevehicleduringdy-
namicdrivingmanoeuvres(e.g.rapidsteering
movements,duringlanechangesoronalter-
natingcurves).
58Controls,Instruments
-Improvedbrakingstabilityincurvesandon
differentorvaryingroadsurfaces.
Readinessforoperation
ThePSMisengagedautomaticallyeverytime
youstarttheengine.
Function
Sensorsatthewheels,brakes,steeringsystem
andenginecontinuouslymeasure:
-Drivingspeed
-Directionoftravel
-Lateralacceleration
-Rateofturnaboutthevehicle'sverticalaxis
ThePSMusesthesevaluestodeterminethe
directionoftraveldesiredbythedriver.
PSMintervenesandcorrectsthecourseifthe
vehicle'sactualdirectiondeviatesfromthe
desiredcourse(steering-wheelposition).It
brakesindividualwheelsasneeded.Ifnecess-
ary,thePSMadditionallyinfluencestheengine
powerorthegear-changingcharacteristicofthe
Tiptronicinordertostabilizethevehicle.
TheeventsbelowinformthedriverofPSMcon-
troloperationsandwarnhimtoadapthisdriving
styletotheroadconditions:
-Theinformationlightintheinstrumentpanel
lightsup.
-Hydraulicnoisescanbeheard.
-Thevehicledeceleratesandsteering-wheel
forcesarealteredasthePSMcontrolsthe
brakes.
-Reducedenginepower.
-Thebrakepedalpulsatesanditspositionis
changedduringbraking.
However,itispossibleatanytimetoachieve
fullvehicledecelerationbyincreasingthefoot
pressureslightlyonthebrakepedal.
Page 59 of 263

Switching
offPSM
[>
Pressthe"PSMOFF"logooftherocker
switch.
PSMisswitchedoffafterabriefdelay.
WithPSMswitchedoff,thePSMOFFwarning
lightintheinstrumentpanelandtherocker
switchindicatorlightarelit.
Duringbraking,thevehicleisstabilizedeven
whenPSMisswitchedoff.
One-sidedspinningofthewheelsisprevented,
evenwithPSMswitchedoff.
PSMshouldalwaysbeswitchedonduring
"normal"driving.
However,itcanbeofadvantagetoswitchoff
PSMtemporarilyinexceptionalsituations:
-Onaloosesurfaceorindeepsnow
-When"rockingthevehiclefree"
-Whenusingsnowchains.
Tiptronicvehicles:WhenthePSMisswitched
offtheslipmonitoringfunctionoftheTiptronicis
alsodeactivated.
Switching
PSMbackon
[>
Presstheindicatorlightintherockerswitch.
PSMisswitchedonafterabriefdelay.
e
Infonnationlight
-ThePSMinformationlightintheinstrument
panellightsupforalampcheckwhentheig-
nitionisswitchedon.
-ThelightindicatesPSMinterventioneven
whenPSMisswitchedoff(brakeregulationin
theeventofone-sidedwheelspin).
4D
Warninglight
-Thewarninglightintheinstrumentpanel
lightsupincombinationwiththeindicatorlight
intherockerswitchforalampcheckwhen
theignitionisswitchedon.
-Incombinationwiththeindicatorlightinthe
rockerswitch,thelightindicatesthatPSMis
switchedoff.
-Thelightsintheinstrumentpanelandinthe
on-boardcomputerindicateadefect.
PSMisoutoforder.
Thefaultshouldberemediedimmediatelyat
anauthorizedPorschedealer.
Towing
Refertothechapter"Towing".
Handbraketests
Handbrake
tests
ontherollerteststandmust
beperformedonlywiththeignitionswitchedoff.
Refertothechapter"Four-wheeldrive".
Controls,Instruments
59
Page 60 of 263

911Carrera4,911Carrera4S
Four-WheelDrive
Withthefour-wheeldrive,theenginepoweris
variablydistributedtothefrontandrearwheels.
Powerdistributionandwheelspeedcompensa-
tionbetweenthefrontandrearaxlesisrealised
withaviscousmultiple-discclutch.
Distributionoftheenginepowerisdependent
uponthewheelspeeddifferencebetweenthe
twoaxles.
Theviscousmultiple-discclutchalwaysdelivers
sufficientdrivepowertothefrontwheels
(approx.5%to
40%)
toensureoptimumtraction
evenonapoorroadsurface.
IncombinationwiththePorscheStabilityMan-
agement(PSMJ,four-wheeldriveensuresopti-
mumhandlingandincreaseddrivingstability.
60Controls,Instruments
/!\.Warning!
Theincreasedcontrolthatisprovided
shouldnotinduceyoutotakegreaterrisks
withyoursafety.Thelimitsdictatedbythe
lawsofphysicscannotbeovercome,even
withfour-wheeldrive.
Theriskofaccidentsduetoinappropriate
speedcannotbereduced,evenbyfour-
wheeldrive.
Thedriverbearstheresponsibilityforall
drivingmaneuvers.
I>Adaptyourdrivingstyletotheprevailingroad
andweatherconditions.
I>Obeyalltrafficlaws.
Dynamometertestingprocedure
SomeU.S.statesandCanadianprovincescon-
ductemissionsinspection/maintenancetesting
involvingtheuseoftwo-wheeldynamometer.
Atwo-wheeleddynamometerisatreadmilltype
deviceuponwhichasingleaxleofthecar,the
drivingaxleofthevehicle,rotatestosimulate
vehicleoperationontheroadwhilethevehicle
remainsstationary.
Your911Carrera4hasafull-timefour-wheel
drivesystemwhichcannotbedisabled.Severe
damagetothepowertraincanresultiftestedon
atwo-wheeldynamometer.
/!\.Warning!
Toavoidseverepowertraindamageanda
possibleunexpectedmovementoftheve-
hicle.
I>Your911Carrera4vehiclemustneverbe
testedonatwo-wheeldynamometer.
I>Advisetheemissionstationofthiswarningbe-
foretestingthevehicle.
Powermeasurement
Powermeasurementsondynamometersarenot
approvedbyPorsche.
Page 61 of 263
Brake
tests
Brake
tests
mustbeperformedonlyonplate-
typeteststandsorrollerteststands.
Thefollowinglimitvaluesmustnotbeexceeded
onrollerteststands:
-Testingspeed4.7mph(7.5km/h)
-Testduration20seconds
Handbraketests
Handbraketestsontherollerteststandmust
beperformedonlywiththeignitionswitchedoff.
Balancingwheelsonthevehicle
Duringfinishbalancingofthewheels,thevehicle
mustbehoistedandthewheelsabletorotate
freely.
Towing
Refertothechapter"Towing".
Controls,Instruments
61
Page 62 of 263
Page 63 of 263
Operation,Instruments
1Sidevent
2Ignition/starterswitchwithsteeringlock
3Spaceforhands-freemicrophonefor
telephone
4Turnsignals/
headlightdimmer/flasherlever
5Instrumentpanel
6Horn
7Windshieldwiper/washerlever
8Emergencyflasherswitch
9Rockerswitchesfor
PorscheStabilityManagement(PSMJ,
footwelllight,
rearwindowwiper
10Readinessdisplayforalarmsystem
11Centralvent
12Cupholder
13Controlpanelforheating,ventilation,
airconditioning
14Rockerswitchesfor
centrallocking,
rearwindowanddoormirrorheating,
rearwindowwiper,
convertibletopoperation
15Speaker
16Lightswitch
17ToggleswitchesforTiptronic
18Operatingleverforon-boardcomputer
19Lockingleverforsteering-wheeladjustment
20Operatingleverforautomaticspeedcontrol
21Wipeintervalcontrol!
rain-sensorsensitivitycontrol
22Rockerswitchesforseatheating
23Rockerswitchforglassslidingroof(Targa)
24Rockerswitchforrollerblind(Targa)
25Radio
26Cigarettelighter
27Glovecompartment
28Interiortemperaturesensor
Controls,Instruments
63
Page 64 of 263
Ignition/StarterSwitchwith
anti-theftSteeringLock
Foryoursafety,
fastensafetybelts.
Seealsothechapteron"Immobilizer".
64Controls,Instruments
Beforestartingtheengine
I>Applythehandbrake.
I>Manualtransmission:
Movethegearshiftleverintoneutral.
Theclutch
pedalmustbedepressedfully
beforethestarterwillengage.
I>Tiptronic:
Movetheselectorleverto"P"or"N".
Switchposition0
Theignitionkeycanbewithdrawninthisposi-
tiononly.
Tiptronicmodels
Theignitionkeycanbewithdrawnonlywhenthe
selectorleverisinthe"P"position.
Thesteeringislockedwhenthekeyiswith-
drawn.
I>
Engagethesteeringlockbymovingthesteer-
ingwheeltotheleftorright.
Turnthesteeringwheeltothelockingposition
beforeyouswitchofftheenginesothatyou
don'thavetoexertyourselfwhenlockingor
unlockingthesteering.